Method For Treating Cancer

ABSTRACT

The present disclosure relates to a method for treating cancer including steps as follows. A chemotherapy drug is administered to a subject in need for a treatment of cancer. Then a composition containing a plurality of chimeric antigen receptor expressing cells is administered to the subject, wherein the chimeric antigen receptor expressing cells expresses a chimeric antigen receptor specific to human leukocyte antigen G (HLA-G).

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number 107132664, filed Sep. 17, 2018, which is herein incorporated by reference.

SEQUENCE LISTING

The sequence listing submitted via EFS, in compliance with 37 CFR § 1.52(e)(5), is incorporated herein by reference. The sequence listing text file submitted via EFS contains the file “CP-4343-US_SequenceListing”, created on Mar. 19, 2019, which is 15,771 bytes in size.

BACKGROUND Technical Field

The present disclosure relates to a method for treating cancer. More particularly, the present disclosure relates to a method for treating cancer with a chemotherapy drug and chimeric antigen receptor expressing cells.

Description of Related Art

Cancer, also known as malignancy, is a state of abnormal proliferation of cells, and these proliferating cells may invade other parts of the body as a disease caused by a malfunction in the control of cell division and proliferation.

The number of people suffering from cancer worldwide has a growing trend. Cancer is one of the top ten causes of death for the Chinese people and has been the top ten causes of death for twenty-seven consecutive years.

Conventional cancer treatments include surgery, radiation therapy, chemotherapy, and target therapy. Cancer immunotherapy is another method for treating cancer except the above methods. The immune system of the patient is activated in the cancer immunotherapy by using tumor cells or tumor antigens to induce specific cellular and humoral immune responses for enhancing the anti-cancer ability of the patient, preventing the growth, spread, and recurrence of tumors, and achieving the purpose of removing or controlling tumors.

There are three main directions for the cancer immunotherapy: the tumor vaccine, the cell therapy and the immune checkpoint inhibitor. The chimeric antigen receptor immune cell technology is one of the cell therapy developing very rapidly in recent years. In conventional technology, the chimeric antigen receptor immune cell transfecting a chimeric protein, which couples the antigen binding portion having capable of recognizing a certain tumor antigen of the antibody to the intracellular portion of the CD3-δ chain or FcεRlγ in vitro, into the immune cell by a transduction method to express the chimeric antigen receptor. The chimeric antigen receptor immune cell technology has a significant therapeutic effect in the treatment of acute leukemia and non-Hodgkin's lymphoma, and it is considered to be one of the most promising treatment for cancer. However, the cell therapy of the chimeric antigen receptor immune cell currently has the following disadvantages: lack of unique tumor-associated antigens, low efficiency of homing of immune cells to tumor sites, and inability to overcome the immunosuppressive microenvironment of solid tumors. Accordingly, the efficacy of the chimeric antigen receptor immune cell in solid tumors is greatly limited.

SUMMARY

According to one aspect of the present disclosure, a method for treating a cancer includes steps as follows. A chemotherapy drug is administered to a subject in need for a treatment of cancer. Then a composition containing a plurality of chimeric antigen receptor expressing cells is administered to the subject, wherein the chimeric antigen receptor expressing cells expresses a chimeric antigen receptor specific to human leukocyte antigen G (HLA-G).

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by Office upon request and payment of the necessary fee. The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:

FIGS. 1A, 1B, 1C, 1D, 1E, 1F, 1G and 1H are analytical results of immunofluorescence staining assay showing a HLA-G expression level of tumor cells treated with a chemotherapy drug.

FIGS. 2A, 2B, 2C, 2D and 2E are analytical results of flow cytometry showing a HLA-G expression of tumor cells treated with a chemotherapy drug.

FIG. 3 is a graph showing an expression level of chimeric antigen receptors in a chimeric antigen receptor expressing cell according to Example 1 of the present disclosure.

FIGS. 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H and 4I show analytical results of tumor cell death induced by chimeric antigen receptor expressing cells according to Example 1 of the present disclosure.

FIG. 5 is a graph showing an expression level of chimeric antigen receptors in a chimeric antigen receptor expressing cell according to Example 2 of the present disclosure.

FIGS. 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H and 6I show analytical results of tumor cell death induced by chimeric antigen receptor expressing cells according to Example 2 of the present disclosure.

FIG. 7 is a graph showing an expression level of a chimeric antigen receptor in a chimeric antigen receptor expressing cell according to Example 3 of the present disclosure.

FIGS. 8A, 8B, 8C, 8D, 8E, 8F, 8G, 8H and 8I show analytical results of tumor cell death induced by chimeric antigen receptor expressing cells according to Example 3 of the present disclosure.

FIG. 9 is a schematic view showing the theoretical structure and mechanism of a chimeric antigen receptor in the plasma membrane of a chimeric antigen receptor expressing cell of the present disclosure.

DETAILED DESCRIPTION

A method for treating cancer is provided. The method includes administering a chemotherapy drug to a subject in need for a treatment of cancer, and administering a composition containing a plurality of chimeric antigen receptor expressing cells to the subject, wherein the chimeric antigen receptor expressing cells expresses a chimeric antigen receptor specific to human leukocyte antigen G (HLA-G). The chemotherapeutic drug can induce the plasma membrane of the tumor cells to express a large amount of the human leukocyte antigen G, thereby enhancing a toxicity of the chimeric antigen receptor cell to the tumor cell.

The term “human leukocyte antigen G (HLA-G)” is a protein that in humans is encoded by the HLA-G gene. The HLA-G belongs to nonclassical class I major histocompatibility complex (MHC) with a heavy chain of approximately 45 kDa. HLA-G is expressed on fetal derived placental cells, and is active in the negative regulation of immune response. HLA-G may play a role in immune tolerance in pregnancy.

According to the method for treating cancer of the present disclosure, the cancer can include breast cancer, polymorphic glioblastoma, pancreatic cancer and ovarian cancer, and the chemotherapy drug can include doxorubicin (Dox), temozolomide (TMZ), gemcitabine (Gem) and carboplatin (CB).

According to the method for treating cancer of the present disclosure, the chimeric antigen receptor can include, in order from an N-terminus to a C-terminus, an anti-HLA-G antibody including an amino acid sequence of SEQ ID NO: 1, an HLA-G receptor including an amino acid sequence of SEQ ID NO: 2, and a costimulatory domain including an amino acid sequence of SEQ ID NO: 3. Preferably, a suicide protein including an amino acid sequence of SEQ ID NO: 4 is linked to the C-terminus of the costimulatory domain, and a 2A peptide including an amino acid sequence of SEQ ID NO: 10 links the HLA-G receptor and the costimulatory domain. In detail, the anti-HLA-G antibody including the amino acid sequence of SEQ ID NO: 1 includes a heavy chain (HC) immunoglobulin variable domain sequence and a light chain (LC) immunoglobulin variable domain sequence. The HC immunoglobulin variable domain sequence includes a CDRH1 including an amino acid sequence of SEQ ID NO: 5, a CDRH2 including an amino acid sequence of SEQ ID NO: 6, and a CDRH3 including an amino acid sequence of SEQ ID NO: 7. The LC immunoglobulin variable domain sequence includes a CDRL2 including an amino acid sequence of SEQ ID NO: 8, and a CDRL3 including an amino acid sequence of SEQ ID NO: 9. The costimulatory domain including an amino acid sequence of SEQ ID NO: 3 is DNAX activating protein 12 (DAP12). The suicide protein including an amino acid sequence of SEQ ID NO: 4 is iCas9 protein.

According to the method for treating cancer of the present disclosure, the chimeric antigen receptor expression plasmid can include a promoter and a nucleic acid encoding the chimeric antigen receptor. The nucleic acid encoding the chimeric antigen receptor can include, in order from a 5′ end to a 3′ end, an anti-HLA-G antibody coding fragment, an HLA-G receptor coding fragment, and a costimulatory domain coding fragment. Preferably, a suicide gene is linked to the 3′ end of the costimulatory domain coding fragment, and a 2A peptide coding fragment links the HLA-G receptor coding fragment and the costimulatory domain coding fragment.

In detail, according to one example of this embodiment, the chimeric antigen receptor expression plasmid is Lenti-EF1a-CAR-100517-S1A plasmid, wherein the insert thereof includes a promoter, an anti-HLA-G antibody coding fragment, an HLA-G receptor coding fragment, and a costimulatory domain coding fragment. The promoter is the EF-1 alpha promoter including a nucleic acid sequence of SEQ ID NO: 16. The anti-HLA-G antibody coding fragment includes the nucleic acid sequence of SEQ ID NO: 11. The HLA-G receptor coding fragment includes the nucleic acid sequence of SEQ ID NO: 12. The costimulatory domain coding fragment includes the nucleic acid sequence of SEQ ID NO: 13. In addition, the insert of the Lenti-EF1a-CAR-100517-S1A plasmid further includes a signal peptide coding fragment including a nucleic acid sequence of SEQ ID NO: 17, the suicide gene including the nucleic acid sequence of SEQ ID NO: 14, and the 2A peptide coding fragment including the nucleic acid sequence of SEQ ID NO: 15. The signal peptide coding fragment is linked to the 5′ end of the anti-HLA-G antibody coding fragment, the suicide gene is linked to the 3′ end of the costimulatory domain coding fragment, and the 2A peptide coding fragment links the HLA-G receptor coding fragment and the costimulatory domain coding fragment. Then, the insert is constructed on Creative Biolabs vector (Creative Biolabs, N.Y., USA) to obtain the Lenti-EF1a-CAR-100517-S1A plasmid. The Creative Biolabs vector is a lentivirus vector system, so that the constructed chimeric antigen receptor expression plasmid can be transfected into expression cells to produce lentiviruses, and the chimeric antigen receptor can be subsequently transduced into the immune cells using lentiviruses.

According to the method for treating cancer of the present disclosure, the chimeric antigen receptor expressing cell can include an immune cell and a chimeric antigen receptor expression plasmid expresses the chimeric antigen receptor specific to HLA-G. The chimeric antigen receptor expressing cell of the present disclosure is obtained by transducing the chimeric antigen receptor of the present disclosure into the immune cell using lentiviruses. Preferably, the immune cell can be a T lymphocyte or a natural killer (NK) cell. More preferably, the NK cell can be a NK-92 cell line or a primary NK cell. In detail, the constructed Lenti-EF1a-CAR-100517-S1A plasmid is transfected into a 293T cell line using lipofectamine 3000 (Invitrogen) to prepare the lentiviruses carrying the chimeric antigen receptor of the present disclosure. For obtaining one example of the chimeric antigen receptor expressing cell, the supernatant containing the prepared lentiviruses and Opti-MEM (Invitrogen) containing 8 μg/ml of polybrene (Sigma-Aldrich) are used to culture the primary T lymphocytes for 3 days to transduce the chimeric antigen receptor of the present disclosure into the primary T lymphocytes. For obtaining another example of the chimeric antigen receptor expressing cell, the supernatant containing the prepared lentiviruses and the Opti-MEM (Invitrogen) containing 50 μg/ml of protamine sulfate (Sigma-Aldrich) are used to culture the primary NK cells or the NK-92 cell line for 7 days to transduce the chimeric antigen receptor of the present disclosure into the primary NK cell or the NK-92 cell line. The obtained chimeric antigen receptor expressing cell has an effect of inducing tumor cell death in mammals, so that the chimeric antigen receptor expressing cell can be used for inhibiting a proliferation of tumor cells in a subject in need for a treatment of a tumor. Preferably, the tumor cell can be a breast cancer cell, a polymorphic glioblastoma cell, a pancreatic cancer cell or an ovarian cancer cell.

Reference will now be made in detail to the present embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

EXAMPLES I. Treatment of Chemotherapy Drug Increases the HLA-G Expression Level on the Plasma Membrane of Tumor Cells

To investigate effect of the treatment of the chemotherapy drug on the tumor cells, the tumor cells are treated with the chemotherapy drug, and then detecting the HLA-G expression level of the tumor cells.

The tumor cells used are human breast cancer cell line MDA-MB-231, human malignant brain tumor cell line DBTRG-05MG (hereinafter referred to as DBTRG), human pancreatic cancer cell line AsPC1, and human ovarian cancer cell line SKOV3. The tumor cell lines used are all purchased from the American Type Culture Collection (ATCC). The human breast cancer cell line MDA-MB-231 is a triple-negative breast cancer cell line, that is, the hormone receptor (ER, PR) and HER-2 receptor thereof are negative, and the human breast cancer cell line MDA-MB-231 is cultured in RPMI culture medium containing 10% fetal bovine serum (FBS). The human malignant brain tumor cell line DBTRG is cultured in DMEM culture medium containing 10% FBS. The human pancreatic cancer cell line AsPC1 is cultured in RPMI culture medium containing 10% FBS. The human ovarian cancer cell line SKOV3 is cultured in McCoy's 5A culture medium containing 10% FBS.

First, the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3 are seeded in a 6-well plate at a density of 2×10⁵ cells/well. The cells are subsequently incubated for 24 hours. Each type of the tumor cells is divided into two groups. In a control, the tumor cells are untreated. In an experiment group, the tumor cells are treated with the chemotherapy drug for 48 hours. The chemotherapy drug used for treating the human breast cancer cell line MDA-MB-231 is doxorubicin (200 nM), the chemotherapy drug used for treating the human malignant brain tumor cell line DBTRG is temozolomide (80 μg/mL), the chemotherapy drug used for treating the human pancreatic cancer cell line AsPC1 is gemcitabine (20 μM), the chemotherapy drug used for treating the human ovarian cancer cell line SKOV3 is carboplatin (20 μM). Then, the HLA-G expression level of the tumor cells are detected by immunofluorescence staining assay and flow cytometry.

Please refer to FIGS. 1A, 1B, 10, 1D, 1E, 1F, 1G and 1H, which are analytical results of immunofluorescence staining assay showing the HLA-G expression level of tumor cells treated with the chemotherapy drug. FIG. 1A is analytical result of immunofluorescence staining assay showing the HLA-G expression level in the control group of the human breast cancer cell line MDA-MB-231, and FIG. 1B is analytical result of immunofluorescence staining assay showing the HLA-G expression level of the human breast cancer cell line MDA-MB-231 treated with doxorubicin (Dox). FIG. 1C is analytical result of immunofluorescence staining assay showing the HLA-G expression level in the control group of the human malignant brain tumor cell line DBTRG, and FIG. 1D is analytical result of immunofluorescence staining assay showing the HLA-G expression level of the human malignant brain tumor cell line DBTRG treated with temozolomide (TMZ). FIG. 1E is analytical result of immunofluorescence staining assay showing the HLA-G expression level in the control group of the human pancreatic cancer cell line AsPC1, and FIG. 1F is analytical result of immunofluorescence staining assay showing the HLA-G expression level of the human pancreatic cancer cell line AsPC1 treated with gemcitabine (Gem). FIG. 1G is analytical result of immunofluorescence staining assay showing the HLA-G expression level in the control group of the human ovarian cancer cell line SKOV3, and FIG. 1H is analytical result of immunofluorescence staining assay showing the HLA-G expression level of the human ovarian cancer cell line SKOV3 treated with carboplatin (CB).

In FIGS. 1A and 1B, treatment of doxorubicin can increase the HLA-G expression level on the plasma membrane of the human breast cancer cell line MDA-MB-231. In FIGS. 1C and 1D, treatment of temozolomide can increase the HLA-G expression level on the plasma membrane of the human malignant brain tumor cell line DBTRG. In FIGS. 1E and 1F, treatment of gemcitabine can increase the HLA-G expression level on the plasma membrane of the human pancreatic cancer cell line AsPC1. In FIGS. 1G and 1H, treatment of carboplatin can increase the HLA-G expression level on the plasma membrane of the human ovarian cancer cell line SKOV3.

Please refer to FIGS. 2A, 2B, 2C, 2D and 2E, which are analytical results of flow cytometry showing a HLA-G expression of tumor cells treated with a chemotherapy drug. FIG. 2A is analytical result of flow cytometry of the human breast cancer cell line MDA-MB-231. FIG. 2B is analytical result of flow cytometry of the human malignant brain tumor cell line DBTRG. FIG. 2C is analytical result of flow cytometry of the human pancreatic cancer cell line AsPC1. FIG. 2D is analytical result of flow cytometry of the human ovarian cancer cell line SKOV3. FIG. 2E is a statistical chart of FIGS. 2A, 2B, 2C and 2D.

In FIG. 2A, the mean fluorescence intensity (MFI) of the control group of the human breast cancer cell line MDA-MB-231 is only 12.27%, while the MFI of the experiment group of the human breast cancer cell line MDA-MB-231 can reach 64.45%, which is statistically significant (p<0.001). In FIG. 2B, the MFI of the control group of the human malignant brain tumor cell line DBTRG is only 14.01%, while the MFI of the experiment group of the human malignant brain tumor cell line DBTRG can reach 22.33%, which is statistically significant (p<0.001). In FIG. 2C, the MFI of the control group of the human pancreatic cancer cell line AsPC1 is only 13.18%, while the MFI of the experiment group of the human pancreatic cancer cell line AsPC1 can reach 41.44%, which is statistically significant (p<0.01). In FIG. 2D, the MFI of the control group of the human ovarian cancer cell line SKOV3 is only 14.69%, while the MFI of the experiment group of the human ovarian cancer cell line SKOV3 can reach 38.58%, which is statistically significant (p 21 0.01).

The results in FIGS. 1A to 2E indicate that the treatment of the chemotherapy drug can increase the HLA-G expression level on the plasma membrane of the tumor cells. Therefore, the method for treating cancer of the present disclosure further administers a composition containing a plurality of chimeric antigen receptor expressing cells to the subject in need for a treatment of cancer, in which the chimeric antigen receptor expressing cells expresses the chimeric antigen receptor specific to HLA-G, in order to enhance the effect of killing tumor cells. The treatment of the chemotherapy drug and the composition containing the chimeric antigen receptor expressing cells can be in a sequence or simultaneous.

II. Method for Treating Cancer of the Present Disclosure 2.1. Example 1

In the following, an Example 1, an Example 2 and an Example 3 will be further provided to illustrate the accompanied efficacies of the method for treating cancer of the present disclosure on inducing tumor cell death. However, the present disclosure is not limited thereto.

The Lenti-EF1a-CAR-100517-S1A plasmid is transduced into the NK-92 cell line to obtain the chimeric antigen receptor expressing cell of Example 1 of the present disclosure, and the expression level of the chimeric antigen receptor of the obtained chimeric antigen receptor expressing cell of Example 1 is analyzed by flow cytometry. Please refer to FIG. 3, which is a graph showing the expression level of chimeric antigen receptors in the chimeric antigen receptor expressing cell according to Example 1 of the present disclosure. FIG. 3 shows the expression level of the chimeric antigen receptor of the parental NK-92 cell line without transducing the chimeric antigen receptor of the present disclosure, and the expression level of the chimeric antigen receptor of the chimeric antigen receptor expressing cell of Example 1 on day 3 and day 7 after transduction the chimeric antigen receptor. In FIG. 3, the MFI of the parental NK-92 cell line is only 9.98%, while the MFI of the chimeric antigen receptor expressing cell of Example 1 on day 3 and day 7 after transduction can reach 20.11% and 65.07%, respectively. The results indicate that the chimeric antigen receptor expressing cell of Example 1 can stably express the chimeric antigen receptor of the present disclosure.

The effects of the method for treating cancer of the present disclosure by using the chimeric antigen receptor expressing cell of Example 1 of the present disclosure on inducing the death of the breast cancer cells, the glioblastoma multiforme cells, the pancreatic cancer cells, and the ovarian cancer cells are further demonstrated in following experiments.

First, the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3 are seeded in a 12-well plate at a density of 1×10⁵ cells/well. The cells are subsequently incubated for 24 hours. Each type of the tumor cells is divided into six groups. In a control, the tumor cells are untreated. In a group 1, the tumor cells are treated with the chemotherapy drug. In a group 2, the tumor cells are treated with the parental NK-92 cell line. In a group 3, the tumor cells are treated with the parental NK-92 cell line and the chemotherapy drug. In the groups 2 and 3, the number of the parental NK-92 cell line treated is 1×10⁵ cells. In a group 4, the tumor cells are treated with the chimeric antigen receptor expressing cell of Example 1. In a group 5, the tumor cells are treated with the chimeric antigen receptor expressing cell of Example 1 and the chemotherapy drug. In the groups 4 and 5, the number of the chimeric antigen receptor expressing cell of Example 1 treated is 1×10⁵ cells. The chemotherapy drug used for treating the human breast cancer cell line MDA-MB-231 is doxorubicin (200 nM), the chemotherapy drug used for treating the human malignant brain tumor cell line DBTRG is temozolomide (80 μg/mL), the chemotherapy drug used for treating the human pancreatic cancer cell line AsPC1 is gemcitabine (20 μM), the chemotherapy drug used for treating the human ovarian cancer cell line SKOV3 is carboplatin (20 μM). The treated cells are stained with Annexin V-FITC and propidium iodide (PI), and the apoptosis and the death of the tumor cells are detected by the flow cytometry. The sum of the percentage of cells stained with Annexin V-FITC and/or PI (that is the percentage of cells in the first quadrant, the second quadrant, and the fourth quadrant of the bivariate flow cytometry scatter plot) are calculated to obtain the cytotoxicity. The results of the cytotoxicity are counted after the three independent trials in each group.

FIGS. 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H and 4I show analytical results of tumor cell death induced by the chimeric antigen receptor expressing cells according to Example 1 of the present disclosure. FIG. 4A is a graph showing the analytical results of the death of the human breast cancer cell line MDA-MB-231 induced by the chimeric antigen receptor expressing cell of Example 1, and FIG. 4B is a statistical chart of FIG. 4A after the three independent trials. FIG. 4C is a graph showing the analytical results of the death of the human malignant brain tumor cell line DBTRG induced by the chimeric antigen receptor expressing cell of Example 1, and FIG. 4D is a statistical chart of FIG. 4C after the three independent trials. FIG. 4E is a graph showing the analytical results of the death of the human pancreatic cancer cell line AsPC1 induced by the chimeric antigen receptor expressing cell of Example 1, and FIG. 4F is a statistical chart of FIG. 4E after the three independent trials. FIG. 4G is a graph showing the analytical results of the death of the human ovarian cancer cell line SKOV3 induced by the chimeric antigen receptor expressing cell of Example 1, and FIG. 4H is a statistical chart of FIG. 4G after the three independent trials. FIG. 4I is a statistical chart of FIGS. 4A, 4C, 4E and 4G after the three independent trials, wherein P represents the parental NK-92 cell line, H represents the chimeric antigen receptor expressing cell of Example 1, D represents doxorubicin, T represents temozolomide, G represents gemcitabine, and C represents carboplatin.

Please refer to FIGS. 4A and 4B. In the control, the death rate of the human breast cancer cell line MDA-MB-231 is only about 10%. In the group 1 treated with the doxorubicin and the group 2 treated with the parental NK-92 cell line, the death rate of the human breast cancer cell line MDA-MB-231 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the doxorubicin and the parental NK-92 cell line, the death rate of the human breast cancer cell line MDA-MB-231 can increase to 40%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 1, the death rate of the human breast cancer cell line MDA-MB-231 is about 60%, and there is a statistically significant difference (p<0.001) compared to the group 2. Furthermore, in the group 5 treated with the doxorubicin and the chimeric antigen receptor expressing cell of Example 1, the death rate of the human breast cancer cell line MDA-MB-231 can reach 80%, and there is a statistically significant difference (p<0.05) compared to the group 4 and a statistically significant difference (p<0.01) compared to the group 3, respectively.

Please refer to FIGS. 4C and 4D. In the control, the death rate of the human malignant brain tumor cell line DBTRG is less than 10%. In the group 1 treated with the temozolomide and the group 2 treated with the parental NK-92 cell line, the death rate of the human malignant brain tumor cell line DBTRG is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the temozolomide and the parental NK-92 cell line, the death rate of the human malignant brain tumor cell line DBTRG can increase to 40%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 1, the death rate of the human malignant brain tumor cell line DBTRG is more than 60%, and there is a statistically significant difference (p<0.001) compared to the group 2. Furthermore, in the group 5 treated with the temozolomide and the chimeric antigen receptor expressing cell of Example 1, the death rate of the human malignant brain tumor cell line DBTRG can reach more than 80%, and there is a statistically significant difference (p<0.05) compared to the group 4 and a statistically significant difference (p<0.001) compared to the group 3, respectively.

Please refer to FIGS. 4E and 4F. In the control, the death rate of the human pancreatic cancer cell line AsPC1 is less than 10%. In the group 1 treated with the gemcitabine and the group 2 treated with the parental NK-92 cell line, the death rate of the human pancreatic cancer cell line AsPC1 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the gemcitabine and the parental NK-92 cell line, the death rate of the human pancreatic cancer cell line AsPC1 can increase to 30%, but there is no statistically significant difference compared to the control. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 1, the death rate of the human pancreatic cancer cell line AsPC1 is approximately 40%, and there is a statistically significant difference (p<0.01) compared to the group 2. Furthermore, in the group 5 treated with the gemcitabine and the chimeric antigen receptor expressing cell of Example 1, the death rate of the human pancreatic cancer cell line AsPC1 can reach 60%, and there is a statistically significant difference (p<0.001) compared to the group 4 and a statistically significant difference (p<0.001) compared to the group 3, respectively.

Please refer to FIGS. 4G and 4H. In the control, the death rate of the human ovarian cancer cell line SKOV3 is less than 10%. In the group 1 treated with the carboplatin and the group 2 treated with the parental NK-92 cell line, the death rate of the human ovarian cancer cell line SKOV3 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the carboplatin and the parental NK-92 cell line, the death rate of the human ovarian cancer cell line SKOV3 can increase to 30%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 1, the death rate of the human ovarian cancer cell line SKOV3 is approximately 40%, and there is a statistically significant difference (p<0.01) compared to the group 2. Furthermore, in the group 5 treated with the carboplatin and the chimeric antigen receptor expressing cell of Example 1, the death rate of the human ovarian cancer cell line SKOV3 can reach 60%, and there is a statistically significant difference (p<0.05) compared to the group 4 and a statistically significant difference (p<0.01) compared to the group 3, respectively.

Please refer to FIG. 4I, the results indicate that the chimeric antigen receptor expressing cell of Example 1 can be used to treat with the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3 for excellent cell killing. Therefore, the chimeric antigen receptor expressing cell of the present disclosure can be used for inhibiting the proliferation of the tumor cells in the subject in need for the treatment of the tumor. Preferably, the tumor cell can be the breast cancer cell, the polymorphic glioblastoma cell, the pancreatic cancer cell or the ovarian cancer cell. Further, the simultaneous treatment of the chemotherapy drug and the chimeric antigen receptor expressing cell of Example 1 can significantly increase the toxic effect on inducing death of the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3. The results indicate that the method for treating cancer of the present disclosure can effectively inhibit the growth of the tumor cells and treat cancer.

2.2. Example 2

The Lenti-EF1a-CAR-100517-S1A plasmid is transduced into the primary NK cell to obtain the chimeric antigen receptor expressing cell of Example 2 of the present disclosure, and the expression level of the chimeric antigen receptor of the obtained chimeric antigen receptor expressing cell of Example 2 is analyzed by the flow cytometry. Please refer to FIG. 5, which is a graph showing an expression level of chimeric antigen receptors in a chimeric antigen receptor expressing cell according to Example 2 of the present disclosure. FIG. 5 shows the expression level of the chimeric antigen receptor of the parental primary NK cell without transducing the chimeric antigen receptor of the present disclosure, and the expression level of the chimeric antigen receptor of the chimeric antigen receptor expressing cell of Example 2 on day 3 and day 7 after transduction the chimeric antigen receptor. In FIG. 5, the MFI of the parental primary NK cell is 22.09%, while the MFI of the chimeric antigen receptor expressing cell of Example 2 on day 3 and day 7 after transduction can reach 29.02% and 50.21%, respectively. The results indicate that the chimeric antigen receptor expressing cell of Example 2 can stably express the chimeric antigen receptor of the present disclosure.

The effects of the method for treating cancer of the present disclosure by using the chimeric antigen receptor expressing cell of Example 2 of the present disclosure on inducing the death of the breast cancer cells, the glioblastoma multiforme cells, the pancreatic cancer cells, and the ovarian cancer cells are further demonstrated in following experiments.

First, the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3 are seeded in a 12-well plate at a density of 1×10⁵ cells/well. The cells are subsequently incubated for 24 hours. Each type of the tumor cells is divided into six groups. In a control, the tumor cells are untreated. In a group 1, the tumor cells are treated with the chemotherapy drug. In a group 2, the tumor cells are treated with the parental primary NK cell. In a group 3, the tumor cells are treated with the parental primary NK cell and the chemotherapy drug. In the groups 2 and 3, the number of the parental primary NK cell treated is 1×10⁵ cells. In a group 4, the tumor cells are treated with the chimeric antigen receptor expressing cell of Example 2. In a group 5, the tumor cells are treated with the chimeric antigen receptor expressing cell of Example 2 and the chemotherapy drug. In the groups 4 and 5, the number of the chimeric antigen receptor expressing cell of Example 2 treated is 1×10⁵ cells. The chemotherapy drug used for treating the human breast cancer cell line MDA-MB-231 is doxorubicin (200 nM), the chemotherapy drug used for treating the human malignant brain tumor cell line DBTRG is temozolomide (80 μg/mL), the chemotherapy drug used for treating the human pancreatic cancer cell line AsPC1 is gemcitabine (20 μM), the chemotherapy drug used for treating the human ovarian cancer cell line SKOV3 is carboplatin (20 μM). The treated cells are stained with Annexin V-FITC and propidium iodide (PI), and the apoptosis and the death of the tumor cells are detected by the flow cytometry. The sum of the percentage of cells stained with Annexin V-FITC and/or PI (that is the percentage of cells in the first quadrant, the second quadrant, and the fourth quadrant of the bivariate flow cytometry scatter plot) are calculated to obtain the cytotoxicity. The results of the cytotoxicity are counted after the three independent trials in each group.

FIGS. 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H and 6I show analytical results of tumor cell death induced by the chimeric antigen receptor expressing cells according to Example 2 of the present disclosure. FIG. 6A is a graph showing the analytical results of the death of the human breast cancer cell line MDA-MB-231 induced by the chimeric antigen receptor expressing cell of Example 2, and FIG. 6B is a statistical chart of FIG. 6A after the three independent trials. FIG. 6C is a graph showing the analytical results of the death of the human malignant brain tumor cell line DBTRG induced by the chimeric antigen receptor expressing cell of Example 2, and FIG. 6D is a statistical chart of FIG. 6C after the three independent trials. FIG. 6E is a graph showing the analytical results of the death of the human pancreatic cancer cell line AsPC1 induced by the chimeric antigen receptor expressing cell of Example 2, and FIG. 6F is a statistical chart of FIG. 6E after the three independent trials. FIG. 6G is a graph showing the analytical results of the death of the human ovarian cancer cell line SKOV3 induced by the chimeric antigen receptor expressing cell of Example 2, FIG. 6H is a statistical chart of FIG. 6G after the three independent trials. FIG. 6I is a statistical chart of FIGS. 6A, 6C, 6E and 6G after the three independent trials, wherein P represents the parental primary NK cell, H represents the chimeric antigen receptor expressing cell of Example 2, D represents doxorubicin, T represents temozolomide, G represents gemcitabine, and C represents carboplatin.

Please refer to FIGS. 6A and 6B. In the control, the death rate of the human breast cancer cell line MDA-MB-231 is only about 10%. In the group 1 treated with the doxorubicin and the group 2 treated with the parental primary NK cell, the death rate of the human breast cancer cell line MDA-MB-231 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the doxorubicin and the parental primary NK cell, the death rate of the human breast cancer cell line MDA-MB-231 can increase to 30%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 2, the death rate of the human breast cancer cell line MDA-MB-231 is more than 50%, and there is a statistically significant difference (p<0.01) compared to the group 2. Furthermore, in the group 5 treated with the doxorubicin and the chimeric antigen receptor expressing cell of Example 2, the death rate of the human breast cancer cell line MDA-MB-231 can reach 80%, and there is a statistically significant difference (p <0.05) compared to the group 4 and a statistically significant difference (p<0.01) compared to the group 3, respectively.

Please refer to FIGS. 6C and 6D. In the control, the death rate of the human malignant brain tumor cell line DBTRG is less than 10%. In the group 1 treated with the temozolomide and the group 2 treated with the parental primary NK cell, the death rate of the human malignant brain tumor cell line DBTRG is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the temozolomide and the parental primary NK cell, the death rate of the human malignant brain tumor cell line DBTRG can increase to about 30%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 2, the death rate of the human malignant brain tumor cell line DBTRG is more than 20%, and there is a statistically significant difference (p<0.05) compared to the group 2. Furthermore, in the group 5 treated with the temozolomide and the chimeric antigen receptor expressing cell of Example 2, the death rate of the human malignant brain tumor cell line DBTRG can reach about 60%, and there is a statistically significant difference (p<0.01) compared to the group 4 and a statistically significant difference (p<0.05) compared to the group 3, respectively.

Please refer to FIGS. 6E and 6F. In the control, the death rate of the human pancreatic cancer cell line AsPC1 is less than 10%. In the group 1 treated with the gemcitabine and the group 2 treated with the parental primary NK cell, the death rate of the human pancreatic cancer cell line AsPC1 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the gemcitabine and the parental primary NK cell, the death rate of the human pancreatic cancer cell line AsPC1 can increase to 30%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 2, the death rate of the human pancreatic cancer cell line AsPC1 is approximately 20%, and there is a statistically significant difference (p<0.01) compared to the group 2. Furthermore, in the group 5 treated with the gemcitabine and the chimeric antigen receptor expressing cell of Example 2, the death rate of the human pancreatic cancer cell line AsPC1 can reach 50%, and there is a statistically significant difference (p<0.01) compared to the group 4 and a statistically significant difference (p<0.05) compared to the group 3, respectively.

Please refer to FIGS. 6G and 6H. In the control, the death rate of the human ovarian cancer cell line SKOV3 is less than 10%. In the group 1 treated with the carboplatin and the group 2 treated with the parental primary NK cell, the death rate of the human ovarian cancer cell line SKOV3 is comparable to that of the control. In the group 3 treated with the carboplatin and the parental primary NK cell, the death rate of the human ovarian cancer cell line SKOV3 can increase to more than 20%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 2, the death rate of the human ovarian cancer cell line SKOV3 is approximately 20%, and there is a statistically significant difference (p<0.05) compared to the group 2. Furthermore, in the group 5 treated with the carboplatin and the chimeric antigen receptor expressing cell of Example 2, the death rate of the human ovarian cancer cell line SKOV3 can reach 50%, and there is a statistically significant difference (p 21 0.01) compared to the group 4 and a statistically significant difference (p<0.05) compared to the group 3, respectively.

Please refer to FIG. 6I, the results indicate that the chimeric antigen receptor expressing cell of Example 2 can be used to treat with the breast cancer cell, the polymorphic glioblastoma cell, the pancreatic cancer cell or the ovarian cancer cell for excellent cell killing. Therefore, the chimeric antigen receptor expressing cell of the present disclosure can be used for inhibiting the proliferation of the tumor cells in the subject in need for the treatment of the tumor. Further, the simultaneous treatment of the chemotherapy drug and the chimeric antigen receptor expressing cell of Example 2 can significantly increase the toxic effect on inducing death of the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3. The results indicate that the method for treating cancer of the present disclosure can effectively inhibit the growth of the tumor cells and treat cancer.

2.3. Example 3

The chimeric antigen receptor of the present disclosure is transduced into the primary T lymphocyte to obtain the chimeric antigen receptor expressing cell of Example 3 of the present disclosure, and the expression level of the chimeric antigen receptor of the obtained chimeric antigen receptor expressing cell of Example 3 is analyzed by the flow cytometry. Please refer to FIG. 7, which is a graph showing an expression level of a chimeric antigen receptor in a chimeric antigen receptor expressing cell according to Example 3 of the present disclosure. FIG. 7 shows the expression level of the chimeric antigen receptor of the parental primary T lymphocyte without transducing the chimeric antigen receptor of the present disclosure, and the expression level of the chimeric antigen receptor of the chimeric antigen receptor expressing cell of Example 3 on day 3 and day 7 after transduction the chimeric antigen receptor. In FIG. 7, the MFI of the parental primary T lymphocyte only is 9.36%, while the MFI of the chimeric antigen receptor expressing cell of Example 3 on day 3 and day 7 after transduction can reach 34.1% and 88.64%, respectively. The results indicate that the chimeric antigen receptor expressing cell of Example 3 can stably express the chimeric antigen receptor of the present disclosure.

The effects of the chimeric antigen receptor expressing cell of Example 3 of the present disclosure on inducing the death of the breast cancer cells, the glioblastoma multiforme cells, the pancreatic cancer cells, and the ovarian cancer cells are further demonstrated in following experiments.

First, the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3 are seeded in a 12-well plate at a density of 1×10⁵ cells/well. The cells are subsequently incubated for 24 hours. Each type of the tumor cells is divided into six groups. In a control, the tumor cells are untreated. In a group 1, the tumor cells are treated with the chemotherapy drug. In a group 2, the tumor cells are treated with the parental primary T lymphocyte. In a group 3, the tumor cells are treated with the parental T lymphocyte and the chemotherapy drug. In the groups 2 and 3, the number of the parental primary T lymphocyte treated is 1×10⁵ cells. In a group 4, the tumor cells are treated with the chimeric antigen receptor expressing cell of Example 3. In a group 5, the tumor cells are treated with the chimeric antigen receptor expressing cell of Example 3 and the chemotherapy drug. In the groups 4 and 5, the number of the chimeric antigen receptor expressing cell of Example 3 treated is 1×10⁵ cells. The chemotherapy drug used for treating the human breast cancer cell line MDA-MB-231 is doxorubicin (200 nM), the chemotherapy drug used for treating the human malignant brain tumor cell line DBTRG is temozolomide (80 μg/mL), the chemotherapy drug used for treating the human pancreatic cancer cell line AsPC1 is gemcitabine (20 μM), the chemotherapy drug used for treating the human ovarian cancer cell line SKOV3 is carboplatin (20 μM). The treated cells are stained with Annexin V-FITC and propidium iodide (PI), and the apoptosis and the death of the tumor cells are detected by the flow cytometry. The sum of the percentage of cells stained with Annexin V-FITC and/or PI (that is the percentage of cells in the first quadrant, the second quadrant, and the fourth quadrant of the bivariate flow cytometry scatter plot) are calculated to obtain the cytotoxicity. The results of the cytotoxicity are counted after the three independent trials in each group.

FIGS. 8A, 8B, 8C, 8D, 8E, 8F, 8G, 8H and 8I show analytical results of tumor cell death induced by the chimeric antigen receptor expressing cells according to Example 3 of the present disclosure. FIG. 8A is a graph showing the analytical results of the death of the human breast cancer cell line MDA-MB-231 induced by the chimeric antigen receptor expressing cell of Example 3, and FIG. 8B is a statistical chart of FIG. 8A after the three independent trials. FIG. 8C is a graph showing the analytical results of the death of the human malignant brain tumor cell line DBTRG induced by the chimeric antigen receptor expressing cell of Example 3, and FIG. 8D is a statistical chart of FIG. 8C after the three independent trials. FIG. 8E is a graph showing the analytical results of the death of the human pancreatic cancer cell line AsPC1 induced by the chimeric antigen receptor expressing cell of Example 3, and FIG. 8F is a statistical chart of FIG. 8E after the three independent trials. FIG. 8G is a graph showing the analytical results of the death of the human ovarian cancer cell line SKOV3 induced by the chimeric antigen receptor expressing cell of Example 3, and FIG. 8H is a statistical chart of FIG. 8G after the three independent trials. FIG. 8I is a statistical chart of FIGS. 8A, 8C, 8E and 8G after the three independent trials, wherein P represents the parental primary T lymphocyte, H represents the chimeric antigen receptor expressing cell of Example 3, D represents doxorubicin, T represents temozolomide, G represents gemcitabine, and C represents carboplatin.

Please refer to FIGS. 8A and 8B. In the control, the death rate of the human breast cancer cell line MDA-MB-231 is only about 10%. In the group 1 treated with the doxorubicin and the group 2 treated with the parental primary T lymphocyte, the death rate of the human breast cancer cell line MDA-MB-231 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the doxorubicin and the parental primary T lymphocyte, the death rate of the human breast cancer cell line MDA-MB-231 can increase to 20%, and there is a statistically significant difference (p<0.01) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 3, the death rate of the human breast cancer cell line MDA-MB-231 is more than 30%, and there is a statistically significant difference (p<0.001) compared to the group 2. Furthermore, in the group 5 treated with the doxorubicin and the chimeric antigen receptor expressing cell of Example 3, the death rate of the human breast cancer cell line MDA-MB-231 can reach about 50%, and there is a statistically significant difference (p<0.05) compared to the group 4 and a statistically significant difference (p<0.001) compared to the group 3, respectively.

Please refer to FIGS. 8C and 8D. In the control, the death rate of the human malignant brain tumor cell line DBTRG is less than 20%. In the group 1 treated with the temozolomide and the group 2 treated with the parental primary T lymphocyte, the death rate of the human malignant brain tumor cell line DBTRG is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the temozolomide and the parental primary T lymphocyte, the death rate of the human malignant brain tumor cell line DBTRG can increase to about 30%, there is no statistically significant difference compared to the control. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 3, the death rate of the human malignant brain tumor cell line DBTRG is more than 50%, and there is a statistically significant difference (p<0.001) compared to the group 2. Furthermore, in the group 5 treated with the temozolomide and the chimeric antigen receptor expressing cell of Example 3, the death rate of the human malignant brain tumor cell line DBTRG can reach about 80%, and there is a statistically significant difference (p<0.05) compared to the group 4 and a statistically significant difference (p<0.001) compared to the group 3, respectively.

Please refer to FIGS. 8E and 8F. In the control, the death rate of the human pancreatic cancer cell line AsPC1 is less than 20%. In the group 1 treated with the gemcitabine and the group 2 treated with the parental primary T lymphocyte, the death rate of the human pancreatic cancer cell line AsPC1 is comparable to that of the control. In the group 3 treated with the gemcitabine and the parental primary T lymphocyte, the death rate of the human pancreatic cancer cell line AsPC1 can increase to 30%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 3, the death rate of the human pancreatic cancer cell line AsPC1 is increased to more than 50%, and there is a statistically significant difference (p<0.001) compared to the group 2. Furthermore, in the group 5 treated with the gemcitabine and the chimeric antigen receptor expressing cell of Example 3, the death rate of the human pancreatic cancer cell line AsPC1 can reach 60%, and there is a statistically significant difference (p<0.01) compared to the group 4 and a statistically significant difference (p<0.01) compared to the group 3, respectively.

Please refer to FIGS. 8G and 8H. In the control, the death rate of the human ovarian cancer cell line SKOV3 is less than 10%. In the group 1 treated with the parental primary T lymphocyte, the death rate of the human ovarian cancer cell line SKOV3 is increased, but there is no statistically significant difference compared to the control. In the group 3 treated with the carboplatin and the parental primary T lymphocyte, the death rate of the human ovarian cancer cell line SKOV3 can increase to about 30%, and there is a statistically significant difference (p<0.05) compared to the group 2. In the group 4 treated with the chimeric antigen receptor expressing cell of Example 3, the death rate of the human ovarian cancer cell line SKOV3 is approximately 60%, and there is a statistically significant difference (p<0.001) compared to the group 2. Furthermore, in the group 5 treated with the carboplatin and the chimeric antigen receptor expressing cell of Example 3, the death rate of the human ovarian cancer cell line SKOV3 can reach more than 60%, and there is a statistically significant difference (p<0.05) compared to the group 4 and a statistically significant difference (p<0.001) compared to the group 3, respectively.

Please refer to FIG. 8I, the results indicate that the chimeric antigen receptor expressing cell of Example 3 can be used to treat with the breast cancer cell, the polymorphic glioblastoma cell, the pancreatic cancer cell or the ovarian cancer cell for excellent cell killing. Therefore, the chimeric antigen receptor expressing cell of the present disclosure can be used for inhibiting the proliferation of the tumor cells in the subject in need for the treatment of the tumor. Further, the simultaneous treatment of the chemotherapy drug and the chimeric antigen receptor expressing cell of Example 3 can significantly increase the toxic effect on inducing death of the human breast cancer cell line MDA-MB-231, the human malignant brain tumor cell line DBTRG, the human pancreatic cancer cell line AsPC1 and the human ovarian cancer cell line SKOV3. The results indicate that the method for treating cancer of the present disclosure can effectively inhibit the growth of the tumor cells and treat cancer.

FIG. 9 is a schematic view showing the theoretical structure and mechanism of the chimeric antigen receptor in the plasma membrane of the chimeric antigen receptor expressing cell of the present disclosure. The chimeric antigen receptor expressing cell of the present disclosure is a genetically engineered NK cell or T cell which expresses the chimeric antigen receptor of the present disclosure, and the chimeric antigen receptor of the present disclosure is a tumor-targeting receptor complex included the anti-HLA-G antibody (scFv), the HLA-G receptor (KIR) and the costimulatory domain (DAP12). Preferably, the chimeric antigen receptor of the present disclosure can further include the suicide protein iCas9. The chimeric antigen receptor expressing cell of the present disclosure can specifically recognize the HLA-G on the tumor plasma membrane. When the tumor cells are treated with the chemotherapy drug, the HLA-G expression on the plasma membrane of the tumor cell can be positively regulated. Accordingly, the chimeric antigen receptor expressing cell of the present disclosure binds to the HLA-G, which is specifically recognized on the surface of the tumor cell, signal transduction is triggered, and a signal cascade is generated to cause activation and proliferation of the chimeric antigen receptor expressing cell of the present disclosure. In turn, it also triggers exocytosis of lytic granules and killing of the target tumor cells.

To sum up, the treatment of the chemotherapy drug can increase the HLA-G expression level on the plasma membrane of tumor cells. The chimeric antigen receptor expressed by the chimeric antigen receptor expressing cell of the present disclosure has excellent specific binding ability to the tumor cells, especially specific binding to HLA-G expressed on the plasma membrane of tumor cells, and can specifically target the tumor cells to avoid the off-target effect, thereby effectively killing the tumor cells. Accordingly, the method for treating cancer of the present disclosure can effectively inhibit the proliferation of the tumor cells in the subject in need for the treatment of the tumor and thereby treat cancer.

Although the present disclosure has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims. 

What is claimed is:
 1. A method for treating a cancer, comprising: administering a chemotherapy drug to a subject in need for a treatment of cancer; and administering a composition containing a plurality of chimeric antigen receptor expressing cells to the subject, wherein the chimeric antigen receptor expressing cells expresses a chimeric antigen receptor specific to human leukocyte antigen G (HLA-G).
 2. The method of claim 1, wherein the cancer comprises a breast cancer, a polymorphic glioblastoma, a pancreatic cancer and an ovarian cancer.
 3. The method of claim 2, wherein the chemotherapy drug comprises doxorubicin, temozolomide, gemcitabine and carboplatin.
 4. The method of claim 1, wherein the chimeric antigen receptor expressing cell comprises an immune cell and a chimeric antigen receptor expression plasmid expresses the chimeric antigen receptor specific to HLA-G.
 5. The method of claim 4, wherein the immune cell is a T lymphocyte.
 6. The method of claim 4, wherein the immune cell is a natural killer (NK) cell.
 7. The method of claim 6, wherein the NK cell is a NK-92 cell line or a primary NK cell.
 8. The method of claim 1, wherein the chimeric antigen receptor comprises, in order from an N-terminus to a C-terminus: an anti-HLA-G antibody comprising an amino acid sequence of SEQ ID NO: 1; an HLA-G receptor comprising an amino acid sequence of SEQ ID NO: 2; and a costimulatory domain comprising an amino acid sequence of SEQ ID NO:
 3. 9. The method of claim 8, wherein the chimeric antigen receptor further comprises a suicide protein comprising an amino acid sequence of SEQ ID NO: 4, and the suicide protein is linked to the C-terminus of the costimulatory domain.
 10. The method of claim 1, wherein the chimeric antigen receptor further comprises a 2A peptide, wherein the 2A peptide links the HLA-G receptor and the costimulatory domain. 